Contents: Valve guides ⇊ Removal and installation ⇊
All valve seats in engines are hidden in guides, are not replaceable and must be trimmed when required for service. Trimming seats requires special tools and experience and should be done in a machine shop. Concentricity of seats should be checked by a mechanic.
Valve guides
Inspection
The valve guides should be cleaned as described above and checked, checking the valve stem diameter and the valve stem-to-guide clearance. Generally, if the engine is leaking oil through the guides (assuming the valve stem seals are OK) and the valve stem diameter is within specification, the guides are worn and need to be replaced.
Valve guides that are not severely worn or warped can, in some cases, be knurled rather than replaced. Knurling is a process in which the metal inside the valve guide bore is moved and raised (forming a very fine criss-cross or spiral pattern), thereby reducing clearance.
Removal and installation
Replacing the valve guide on all Accords and Preludes requires heating the cylinder head to 150°C, then removing the guide from the head with a hammer and precision punch. If you don't want to bake an oily cylinder head in an oven, take the head to a machine shop and have a mechanic replace the guides.
[Original material on the website HONDABOOK]